The present invention relates to an archery broadhead, and more particularly, to a broadhead with helical blades having elongate cutting edges which impart spin to the arrow in flight to increase accuracy, penetration and hemorrhaging of the target animal.
A bow hunter's goal at all times is accurately place a shot in a killing zone of a big game animal with maximum penetration to establish excessive hemorrhaging and ultimately result in a quick kill and successful animal retrieval thereby avoiding excessive tracking efforts, prolonged pain and suffering to be experience by the animal.
To achieve the hunter's goal, the archery industry has provided faster shooting and more powerful bows with increased percentage of “let off” allowing the hunter to hold the drawn bow longer while aiming. However, with faster and more powerful bows comes problems associated with the accuracy of arrow placement. One aspect to assist in arrow accuracy and stabilization has been the use of offset arrow feather fletching which brings a spin to the arrow to stabilize the arrow during flight and to increase its accuracy.
Broadheads at the tip end of the arrow cut into the target animal to establish hemorrhaging as they pass through vital organs. These known conventional broadhead blades seriously impede the rotation of the arrow and may in fact cause the arrow to wobble and deflect offline.
Expandable broadheads have been developed which maintain a narrow, low profile during flight. The expandable broadheads are effective if the hunter makes an ideal shot, including a successful projected shot angle to avoid bones. Bones cause the arrow to deflect and many times break the blade or divert the blade away from intended vital organs. Also, once the expanded broadhead has stopped, the blades tend to fold back to a non-cutting position, at which point the arrow is easily removed by the animal's mouth, running motion, or trail brush. This eliminates further organ damage and prolonged recovery of the wounded animal.
U.S. Pat. No. 6,319,161 discloses an arrowhead having a plurality of cutting blades with spiral edges to collectively define a generally circular cutting envelope when the arrowhead rotates in flight. However, because the spiral blades have only the leading end locked down to the arrowhead, they appear to be fragile and may easily break upon impact with the target. This is because they lack appropriate strengthening connections between the forward and rearward blade components and are completely mounted within a single slot within the ferrule.
U.S. Pat. No. 6,663,518 is similar to the '161 helical blade design, but less drastic. The individual blades have a rearwardly located slight airfoil shape which may slightly assist in rotating the blade but offer little assistance in penetration.
There is a need for a broadhead with helical blades that impart spin to the arrow in flight but have improved strength and mounting characteristics that provide increased penetration into the target animal which results in massive tissue destruction and hemorrhaging without breakage caused by hitting bone structures.